Adsorption Of CH3SH Research Articles

The Adsorption of Sulfur‐Compounds on Cu(II)Y Zeolite

AbstractThe adsorption of H2S, CH3SH and CS2 on Cu(II)Y zeolite reveals an affinity sequence CH3SH » CS2 > H2S. Very strong displacement effects of CS2 and H2S by SH were observed when binary mixtures of CS2/CH3SH and CS2/H2S were contacted with Cu(II)Y. In ternary mixtures H2S is displaced by both, CS2 and CH3SH while CS2 is displaced by CH3SH. The interaction between the Cu(II)Y and the different S‐compounds is studied by infrared spectroscopy. A strong dissociative adsorption, creating new hydroxyl groups, is only observed for the CH3SH adsorption in the Cu(II)Y zeolite and reflects the high selectivity of Cu(II)Y for CH3SH compared to H2S and CS2.

Comparative adsorption of H2S, CH3SH and (CH3)2S on alumina. Structure of species and adsorption sites

The adsorption of H2S, CH3SH and (CH3)2S has been studied by gravimetry and infrared spectroscopy. Some experiments have been carried out with preadsorbed pyridine as a poison. The results show that (CH3)2S is bonded to Lewis acid sites and that 60 µmol g–1 are irreversibly coordinated to stronger sites of this type. Dissociative chemisorption has been observed for H2S and CH3SH. Poisoning experiments lead us to conclude that the first adsorption steps involve either a coordinative adsorption (ca. 30 µmol g–1) or a hydrogen bond between a surface basic oxygen atom and the H atom of the SH bond (ca. 50 µmol g–1). The reversible adsorption of CH3SH is thought to occur by these two processes besides another one in which the S atom is H bonded to a hydroxyl surface group. These results clarify the nature of the adsorption sites of alumina.